Precursors for the atomic layer deposition of transition metals and methods of use

ABSTRACT

Metal coordination complexes comprising at least one diazabutadiene based ligand having a structure represented by:where A1, A2, A3, and A4 are atoms in a 6-membered ring and are independently selected from C, N, O, S, and P; and where R1, R2, R3, R4, R5, and R6 are independently selected from the group consisting of H, amino groups, C1-C6 alkyl groups, or C4-10 cycloalkyl groups; and further provided that alkyl groups may optionally contain silicon; and where the metal coordination complex is capable of participating in a Diels-Alder type reaction with a dienophile. Processing methods using the metal coordination complexes are also described.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.62/483,101, filed Apr. 7, 2017, the entire disclosure of which is herebyincorporated by reference herein.

FIELD

Embodiments of the disclosure relate to metal complex precursors forthin film deposition through CVD or ALD processes. More particularly,embodiments of the disclosure are directed to metal complex precursorscapable of participation in a Diels-Alder type reaction and methods ofuse.

BACKGROUND

The semiconductor industry continues to strive for continuous deviceminiaturization that is driven by the need for mobile andhigh-performance systems in emerging industries such as autonomousvehicles, virtual reality, and future mobile devices. To accomplish thisfeat, new, high-performance materials are needed to circumvent inherentengineering and physics issues encountered in rapid reduction offeatures in microelectronic devices.

Ideally, thin-films of metal would be deposited using thin-filmdeposition techniques such as Chemical Vapor Deposition (CVD) and AtomicLayer Deposition (ALD) owing to their inherent ability to depositmaterial in a high-throughput, conformal, and precise fashion.

Chemical vapor deposition (CVD) is one of the most common depositionprocesses employed for depositing layers on a substrate. CVD is aflux-dependent deposition technique that uses precise control of thesubstrate temperature and the precursors introduced into the processingchamber in order to produce a desired layer of uniform thickness. Thereaction parameters become more critical as substrate size increases,creating a need for more complexity in chamber design and gas flowtechnique to maintain adequate uniformity.

A variant of CVD that demonstrates excellent step coverage is cyclicaldeposition or atomic layer deposition (ALD). Cyclical deposition isbased upon atomic layer epitaxy (ALE) and employs chemisorptiontechniques to deliver precursor molecules on a substrate surface insequential cycles. The cycle exposes the substrate surface to a firstprecursor, a purge gas, a second precursor and the purge gas. The firstand second precursors react to form a product compound as a film on thesubstrate surface. The cycle is repeated to form the layer to a desiredthickness.

Processing a metal precursor often involves using oxygen or an oxidizingco-reagent. Use of oxygen and oxidizing co-reagents can be incompatiblewith other adjacent films in the device stack. Therefore, there is aneed in the art for metal precursors and co-reagents that react to formmetal and metal-based thin films without an oxidizing co-reagent.

SUMMARY

One or more embodiments of the disclosure are directed to a metalcoordination complex comprising at least one ligand according to:

wherein A₁, A₂, A₃, and A₄ are atoms in a 6-membered ring and areindependently selected from C, N, O, S, and P; and wherein R₁, R₂, R₃,R₄, R₅, and R₆ are independently selected from the group consisting ofH, amino groups, C1-C6 alkyl groups, or C4-10 cycloalkyl groups; furtherprovided that alkyl groups may optionally contain silicon; and whereinthe metal coordination complex is capable of participating in aDiels-Alder type reaction with a dienophile.

Additional embodiments of the disclosure are directed to A metalcoordination complex of the general formula:

wherein A₁, A₂, A₃, and A₄ are atoms in a 6-membered ring and areindependently selected from C, N, O, S, and P; and wherein R₁, R₂, R₃,R₄, R₅, and R₆ are independently selected from the group consisting ofH, amino groups, C1-C6 alkyl groups, or C4-10 cycloalkyl groups; furtherprovided that alkyl groups may optionally contain silicon; X in ananionic ligand; Y is a neutral ligand; a is 1-4; b is 0-8; c is 0-8; andwherein the metal coordination complex is capable of participating in aDiels-Alder type reaction with a dienophile.

Further embodiments of the disclosure are directed to a processingmethod comprising exposing a substrate to a first reactive gascomprising a metal coordination complex and a second reactive gascomprising a dienophile to form a metal-containing film through aDiels-Alder type reaction, the metal coordination complex comprising atleast one ligand according to

wherein A₁, A₂, A₃, and A₄ are atoms in a 6-membered ring and areindependently selected from C, N, O, S, and P; and wherein R₁, R₂, R₃,R₄, R₅, and R₆ are independently selected from the group consisting ofH, amino groups, C1-C6 alkyl groups, or C4-10 cycloalkyl groups; andfurther provided that alkyl groups may optionally contain silicon.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the disclosurecan be understood in detail, a more particular description of thedisclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of the disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may admit to otherequally effective embodiments.

The FIGURE illustrates an exemplary process sequence for the formationof a metal layer using a two pulse cyclical deposition techniqueaccording to one embodiment described herein.

DETAILED DESCRIPTION

Embodiments of the disclosure provide precursors and processes fordepositing metal-containing films. The process of various embodimentsuses vapor deposition techniques, such as an atomic layer deposition(ALD) or chemical vapor deposition (CVD) to provide metal films.

A “substrate surface”, as used herein, refers to any portion of asubstrate or portion of a material surface formed on a substrate uponwhich film processing is performed. For example, a substrate surface onwhich processing can be performed include materials such as silicon,silicon oxide, silicon nitride, doped silicon, germanium, galliumarsenide, glass, sapphire, and any other materials such as metals, metalnitrides, metal alloys, and other conductive materials, depending on theapplication. Substrates include, without limitation, semiconductorwafers. Substrates may be exposed to a pretreatment process to polish,etch, reduce, oxidize, hydroxylate, anneal, UV cure, e-beam cure and/orbake the substrate surface. In addition to film processing directly onthe surface of the substrate itself, in the present invention, any ofthe film processing steps disclosed may also be performed on anunderlayer formed on the substrate as disclosed in more detail below,and the term “substrate surface” is intended to include such underlayeras the context indicates. Thus for example, where a film/layer orpartial film/layer has been deposited onto a substrate surface, theexposed surface of the newly deposited film/layer becomes the substratesurface. Substrates may have various dimensions, such as 200 mm or 300mm diameter wafers, as well as, rectangular or square panes. In someembodiments, the substrate comprises a rigid discrete material.

“Atomic layer deposition” or “cyclical deposition” as used herein refersto the sequential exposure of two or more reactive compounds to deposita layer of material on a substrate surface. As used in thisspecification and the appended claims, the terms “reactive compound”,“reactive gas”, “reactive species”, “precursor”, “process gas” and thelike are used interchangeably to mean a substance with a species capableof reacting with the substrate surface or material on the substratesurface in a surface reaction (e.g., chemisorption, oxidation,reduction, cycloaddition). The substrate, or portion of the substrate,is exposed sequentially to the two or more reactive compounds which areintroduced into a reaction zone of a processing chamber. In atime-domain ALD process, exposure to each reactive compound is separatedby a time delay to allow each compound to adhere and/or react on thesubstrate surface and then be purged from the processing chamber. In aspatial ALD process, different portions of the substrate surface, ormaterial on the substrate surface, are exposed simultaneously to the twoor more reactive compounds so that any given point on the substrate issubstantially not exposed to more than one reactive compoundsimultaneously. As used in this specification and the appended claims,the term “substantially” used in this respect means, as will beunderstood by those skilled in the art, that there is the possibilitythat a small portion of the substrate may be exposed to multiplereactive gases simultaneously due to diffusion, and that thesimultaneous exposure is unintended.

In one aspect of a time-domain ALD process, a first reactive gas (i.e.,a first precursor or compound A) is pulsed into the reaction zonefollowed by a first time delay. Next, a second precursor or compound Bis pulsed into the reaction zone followed by a second delay. During eachtime delay, a purge gas, such as argon, is introduced into theprocessing chamber to purge the reaction zone or otherwise remove anyresidual reactive compound or reaction by-products from the reactionzone. Alternatively, the purge gas may flow continuously throughout thedeposition process so that only the purge gas flows during the timedelay between pulses of reactive compounds. The reactive compounds arealternatively pulsed until a desired film or film thickness is formed onthe substrate surface. In either scenario, the ALD process of pulsingcompound A, purge gas, compound B and purge gas is a cycle. A cycle canstart with either compound A or compound B and continue the respectiveorder of the cycle until achieving a film with the predeterminedthickness.

In an embodiment of a spatial ALD process, a first reactive gas andsecond reactive gas (e.g., hydrogen radicals) are deliveredsimultaneously to the reaction zone but are separated by an inert gascurtain and/or a vacuum curtain. The substrate is moved relative to thegas delivery apparatus so that any given point on the substrate isexposed to the first reactive gas and the second reactive gas.

In an aspect of a spatial ALD process, a first reactive gas and secondreactive gas (e.g., hydrogen radicals) are delivered simultaneously tothe reaction zone but are separated by an inert gas curtain and/or avacuum curtain. The substrate is moved relative to the gas deliveryapparatus so that any given point on the substrate is exposed to thefirst reactive gas and the second reactive gas.

One or more embodiments of the disclosure are directed to a class ofmetal coordination complexes with diazabutadiene ligands for CVD and ALDprocesses. The diazabutadiene ligand is represented by the formula (I)

wherein A₁, A₂, A₃, and A₄ are atoms in a 6-membered ring and areindependently selected from C, N, O, S, and P; and wherein R₁, R₂, R₃,R₄, R₅, and R₆ are independently selected from the group consisting ofH, amino groups, C1-C6 alkyl groups, or C4-10 cycloalkyl groups, andfurther provided that these alkyl groups may optionally contain silicon.

As used in this manner, the letter “C” followed by a numeral (e.g.,“C4”) means that the substituent comprises the specified number ofcarbon atoms (e.g., C4 comprises four carbon atoms).

Modification of the R₁ and R₆ groups has been found to alter the orbitalsymmetry of the diazabutadiene-based ligand. In some embodiments, theorbital symmetry of the ligand is modified so as to allow a Diels Aldertype reaction.

A ligand similar to formula (I) can be reacted with an alkene (or asuitable dienophile) to produce a quinoxaline derivative in aDiels-Alder type reaction. The Diels-Alder reaction process can be usedas a substitute for or in conjunction with oxidizing reagents in CVD andALD metal deposition processes.

The metal complex is introduced into the process region of a processingchamber and allowed to react with the substrate surface. After the metalcomplex has reacted with the substrate surface to produce ametal-surface bond, a dienophile is introduced into the process regionand a Diels-Alder type reaction takes place. The reaction results in themetal bonded to the surface and a quinoxaline derivative.

In some embodiments, R₁ and R₆ are a trimethylsilyl group. In someembodiments the metal atom is selected from Mn, Re, Fe, Ru, Os, Co, Rh,Ir, Ni, Pd, Pt, Cu, Ag, and Au or combinations thereof. In someembodiments the metal atom is selected from Fe, Ru, Os, Co, Rh, Ir, Ni,Pd, and Pt or combinations thereof.

The metal coordination complex on the surface of the substrate isreacted with a dienophile to deposit the metal film. The dienophile ofsome embodiments comprises an alkene. The dienophile of someembodiments, comprises an alkyne.

In additional embodiments, the metal coordination complex is of thegeneral formula

wherein A₁, A₂, A₃, and A₄ are atoms in a 6-membered ring and areindependently selected from C, N, O, S, and P; and wherein R₁, R₂, R₃,R₄, R₅, and R₆ are independently selected from the group consisting ofH, amino groups, C1-C6 alkyl groups, or C4-10 cycloalkyl groups; andfurther provided that alkyl groups may optionally contain silicon; X inan anionic ligand; Y is a neutral ligand; a is 1-4; b is 0-8; c is 0-8;and wherein the metal coordination complex is capable of participatingin a Diels-Alder type reaction with a dienophile.

In some embodiments, the complex includes at least one anionic ligand(X). The anionic ligand of some embodiments comprises one or more of F⁻,Cl⁻, Br⁻, I⁻, OH⁻ or CN⁻.

In some embodiments, the complex includes at least one neutral donorligand (Y). In some embodiments, the neutral donor ligand comprises asolvent molecule. The neutral donor ligand of some embodiments comprisesone or more of H₂O, NO, NR″₃, PR″₃, dimethyl ether (DME),tetrahydrofuran (THF), tetramethylethylenediamine (TMEDA), CO,acetonitrile, pyridine, ammonia, ethylenediamine, and/ortriphenylphosphine. where each R″ is independently H, C1-C6 alkyl oraryl group.

The number of diazadiene-based ligands, anionic ligands and neutralligands can vary. In some embodiments, the combination of ligandsresults in a metal coordination complex in which the metal atom has anoxidation state of neutral, +1, +2, +3, +4, +5, +6, +7, +8 or +9.

In some embodiments, a processing method comprises exposing a substrateto a first reactive gas comprising a metal coordination complex and asecond reactive gas comprising a dienophile to form a metal-containingfilm through a Diels-Alder type reaction, the metal coordination complexcomprising at least one ligand according to

wherein A₁, A₂, A₃, and A₄ are atoms in a 6-membered ring and areindependently selected from C, N, O, S, and P; and wherein R₁, R₂, R₃,R₄, R₅, and R₆ are independently selected from the group consisting ofH, amino groups, C1-C6 alkyl groups, or C4-10 cycloalkyl groups; andfurther provided that alkyl groups may optionally contain silicon.

In some embodiments, the substrate is exposed to the first reactive gasand the second reactive gas sequentially. In some embodiments, thesubstrate is exposed to the first reactive gas and the second reactivegas simultaneously.

In some embodiments, the second reactive gas comprises one or more of analkene or an alkyne. In some embodiments, the second reactive gascomprises one or more of H₂, NH₃, hydrazine, hydrazine derivatives, O₂,O₃, H₂O, NO₂, N₂O or plasmas thereof. In some embodiments, the secondreactive gas comprises a silicon-containing compound and themetal-containing film comprises metal silicide (MSi_(x)).

In some embodiments, the metal-containing film comprises greater than orequal to about 95 percent metal. In some embodiments the metal atom isselected from the transition metals from Groups 7 to 11 on the PeriodicTable. In some embodiments the metal atom is selected from thetransition metals from Groups 8 to 10 on the Periodic Table.

The metal coordination complex can be a monomer or a dimer. In someembodiments, the metal coordination complex is a dimer with a ligandlinking two metal atoms (e.g., Co). In some embodiments, the metalcoordination complex is a dimer with the two metal atoms linkeddirectly.

The complexes of some embodiments may react as precursors in an ALD orCVD process to form thin films. Suitable reactants include, but are notlimited to, alkenes, alkynes, H₂, NH₃, hydrazine, hydrazine derivativesand other co-reactants to make metal or M_(x)N_(y) films. Suitablereactants also include, but are not limited to, O₂, O₃, water and otheroxygen based co-reactants to make metal or M_(x)O_(y) films. Plasmatreatments of a co-reactant or as a post-treatment may also be used.

The FIGURE depicts a method for forming an metal-containing layer on asubstrate in accordance with one or more embodiment of the disclosure.The method 100 generally begins at 102, where a substrate, having asurface upon which an metal-containing layer is to be formed is providedand placed into a processing chamber. As used herein, a “substratesurface” refers to any substrate surface upon which a layer may beformed. The substrate surface may have one or more features formedtherein, one or more layers formed thereon, and combinations thereof.The substrate (or substrate surface) may be pretreated prior to thedeposition of the metal-containing layer, for example, by polishing,etching, reduction, oxidation, halogenation, hydroxylation, annealing,baking, or the like.

The substrate may be any substrate capable of having material depositedthereon, such as a silicon substrate, a III-V compound substrate, asilicon germanium (SiGe) substrate, an epi-substrate, asilicon-on-insulator (SOI) substrate, a display substrate such as aliquid crystal display (LCD), a plasma display, an electro luminescence(EL) lamp display, a solar array, solar panel, a light emitting diode(LED) substrate, a semiconductor wafer, or the like. In someembodiments, one or more additional layers may be disposed on thesubstrate such that the metal-containing layer may be at least partiallyformed thereon. For example, in some embodiments, a layer comprising ametal, a nitride, an oxide, or the like, or combinations thereof may bedisposed on the substrate and may have the metal containing layer formedupon such layer or layers.

In some embodiments, the substrate may be exposed to an optional soakprocess 103 prior to beginning the cyclical deposition process to forman metal-containing layer on the substrate (as discussed below at 104),as shown in phantom at 103. In one or more embodiments, the method ofdepositing the metal-containing layer on the substrate 104 does notinclude a soaking process.

At 104, an metal-containing layer is formed on the substrate. Themetal-containing layer may be formed via a cyclical deposition process,such as atomic layer deposition (ALD), or the like. In some embodiments,the forming of an metal-containing layer via a cyclical depositionprocess may generally comprise exposing the substrate to two or moreprocess gases sequentially. In time-domain ALD embodiments, exposure toeach of the process gases are separated by a time delay/pause to allowthe components of the process gases to adhere and/or react on thesubstrate surface. Alternatively, or in combination, in someembodiments, a purge may be performed before and/or after the exposureof the substrate to the process gases, wherein an inert gas is used toperform the purge. For example, a first process gas may be provided tothe process chamber followed by a purge with an inert gas. Next, asecond process gas may be provided to the process chamber followed by apurge with an inert gas. In some embodiments, the inert gas may becontinuously provided to the process chamber and the first process gasmay be dosed or pulsed into the process chamber followed by a dose orpulse of the second process gas into the process chamber. In suchembodiments, a delay or pause may occur between the dose of the firstprocess gas and the second process gas, allowing the continuous flow ofinert gas to purge the process chamber between doses of the processgases.

In spatial ALD embodiments, exposure to each of the process gases occurssimultaneously to different parts of the substrate so that one part ofthe substrate is exposed to the first reactive gas while a differentpart of the substrate is exposed to the second reactive gas (if only tworeactive gases are used). The substrate is moved relative to the gasdelivery system so that each point on the substrate is sequentiallyexposed to both the first and second reactive gases. In any embodimentof a time-domain ALD or spatial ALD process, the sequence may berepeated until a predetermined layer thickness is formed on thesubstrate surface.

A “pulse” or “dose” as used herein is intended to refer to a quantity ofa source gas that is intermittently or non-continuously introduced intothe process chamber. The quantity of a particular compound within eachpulse may vary over time, depending on the duration of the pulse. Aparticular process gas may include a single compound or amixture/combination of two or more compounds, for example, the processgases described below.

The durations for each pulse/dose are variable and may be adjusted toaccommodate, for example, the volume capacity of the processing chamberas well as the capabilities of a vacuum system coupled thereto.Additionally, the dose time of a process gas may vary according to theflow rate of the process gas, the temperature of the process gas, thetype of control valve, the type of process chamber employed, as well asthe ability of the components of the process gas to adsorb onto thesubstrate surface. Dose times may also vary based upon the type of layerbeing formed and the geometry of the device being formed. A dose timeshould be long enough to provide a volume of compound sufficient toadsorb/chemisorb onto substantially the entire surface of the substrateand form a layer of a process gas component thereon.

The process of forming the metal-containing layer at step 104 may beginby exposing the substrate to a first reactive gas. In some embodiments,the first reactive gas comprises an metal precursor (also referred to asan metal-containing gas, and the like) and is exposed to the substratefor a first period of time, as shown at 106.

The metal-containing gas may be provided in one or more pulses orcontinuously. The flow rate of the metal-containing gas can be anysuitable flow rate including, but not limited to, flow rates is in therange of about 1 to about 5000 sccm, or in the range of about 2 to about4000 sccm, or in the range of about 3 to about 3000 sccm or in the rangeof about 5 to about 2000 sccm. The metal-containing gas can be providedat any suitable pressure including, but not limited to, a pressure inthe range of about 5 mTorr to about 25 Torr, or in the range of about100 mTorr to about 20 Torr, or in the range of about 5 Torr to about 20Torr, or in the range of about 50 mTorr to about 2000 mTorr, or in therange of about 100 mTorr to about 1000 mTorr, or in the range of about200 mTorr to about 500 mTorr.

The period of time that the substrate is exposed to the metal-containinggas may be any suitable amount of time necessary to allow the metalprecursor to form an adequate nucleation layer atop the substratesurfaces. For example, the process gas may be flowed into the processchamber for a period of about 0.1 seconds to about 90 seconds. In sometime-domain ALD processes, the metal-containing gas is exposed thesubstrate surface for a time in the range of about 0.1 sec to about 90sec, or in the range of about 0.5 sec to about 60 sec, or in the rangeof about 1 sec to about 30 sec, or in the range of about 2 sec to about25 sec, or in the range of about 3 sec to about 20 sec, or in the rangeof about 4 sec to about 15 sec, or in the range of about 5 sec to about10 sec.

In some embodiments, an inert gas may additionally be provided to theprocess chamber at the same time as the metal-containing gas. The inertgas may be mixed with the metal-containing gas (e.g., as a diluent gas)or separately and can be pulsed or of a constant flow. In someembodiments, the inert gas is flowed into the processing chamber at aconstant flow in the range of about 1 to about 10000 sccm. The inert gasmay be any inert gas, for example, such as argon, helium, neon,combinations thereof, or the like. In one or more embodiments, themetal-containing gas is mixed with argon prior to flowing into theprocess chamber.

The temperature of the substrate during deposition can be controlled,for example, by setting the temperature of the substrate support orsusceptor. In some embodiments the substrate is held at a temperature inthe range of about 100° C. to about 600° C., or in the range of about200° C. to about 525° C., or in the range of about 300° C. to about 475°C., or in the range of about 350° C. to about 450° C. In one or moreembodiments, the substrate is maintained at a temperature less thanabout 475° C., or less than about 450° C., or less than about 425° C.,or less than about 400° C., or less than about 375° C.

In addition to the foregoing, additional process parameters may beregulated while exposing the substrate to the metal-containing processgas. For example, in some embodiments, the process chamber may bemaintained at a pressure of about 0.2 to about 100 Torr, or in the rangeof about 0.3 to about 90 Torr, or in the range of about 0.5 to about 80Torr, or in the range of about 1 to about 50 Torr.

Next, at 108, the process chamber (especially in time-domain ALD) may bepurged using an inert gas. (This may not be needed in spatial ALDprocesses as there is a gas curtain separating the reactive gases.) Theinert gas may be any inert gas, for example, such as argon, helium,neon, or the like. In some embodiments, the inert gas may be the same,or alternatively, may be different from the inert gas provided to theprocess chamber during the exposure of the substrate to the firstprocess gas at 106. In embodiments where the inert gas is the same, thepurge may be performed by diverting the first process gas from theprocess chamber, allowing the inert gas to flow through the processchamber, purging the process chamber of any excess first process gascomponents or reaction byproducts. In some embodiments, the inert gasmay be provided at the same flow rate used in conjunction with the firstprocess gas, described above, or in some embodiments, the flow rate maybe increased or decreased. For example, in some embodiments, the inertgas may be provided to the process chamber at a flow rate of greaterthan 0 to about 10000 sccm to purge the process chamber. In spatial ALD,purge gas curtains are maintained between the flows of reactive gasesand purging the process chamber may not be necessary. In someembodiments of a spatial ALD process, the process chamber or region ofthe process chamber may be purged with an inert gas.

The flow of inert gas may facilitate removing any excess first processgas components and/or excess reaction byproducts from the processchamber to prevent unwanted gas phase reactions of the first and secondprocess gases. For example, the flow of inert gas may remove excessmetal-containing gas from the process chamber, preventing a reactionbetween the metal precursor and a subsequent reactive gas.

Next, at 110, the substrate is exposed to a second process gas for asecond period of time. The second process gas reacts with themetal-containing compound on the substrate surface to create a depositedfilm. The second process gas can impact the resulting metal film. Forexample, when the second process gas is H₂, an metal film is deposited,but when the second reactive gas is silane or disilane, an metalsilicide film may be deposited.

In some embodiments, the second reactive gas comprises one or more of analkene, an alkyne, H₂, NH₃, hydrazine, hydrazine derivatives, or plasmasthereof. In some embodiments, the second reactive gas is selected todeposit a metal film (e.g., an metal film) or a metal nitride (e.g.,M_(x)N_(y)) on the substrate.

In some embodiments, the second reactive gas comprises one or more ofO₂, O₃, H₂O, NO₂, N₂O, or plasmas thereof. In one or more embodiments,the second reactive gas is selected to deposit a metal oxide, metalnitride or metal oxynitride film.

In some embodiments, the second reactive gas comprises a compoundselected to form a metal silicide, metal silicate, metal carbide, metalcarbonitride, metal oxycarbide, metal oxycarbonitride, or a metal filmincluding one or more of O, N, C, Si or B.

In some embodiments, the second reactive gas comprises hydrogen and theresulting film formed is an metal film. The hydrogen gas may be suppliedto the substrate surface at a flow rate greater than themetal-containing gas concentration. In one or more embodiments, the flowrate of H₂ is greater than about 1 time that of the metal-containinggas, or about 100 times that of the metal-containing gas, or in therange of about 3000 to 5000 times that of the metal-containing gas. Thehydrogen gas can be supplied, in time-domain ALD, for a time in therange of about 1 sec to about 30 sec, or in the range of about 5 sec toabout 20 sec, or in the range of about 10 sec to about 15 sec. Thehydrogen gas can be supplied at a pressure in the range of about 1 Torrto about 30 Torr, or in the range of about 5 Torr to about 25 Torr, orin the range of about 10 Torr to about 20 Torr, or up to about 50 Torr.The substrate temperature can be maintained at any suitable temperature.In one or more embodiments, the substrate is maintained at a temperatureless than about 475° C., or at a temperature about the same as that ofthe substrate during the metal-containing film deposition.

In some embodiments, the second reactive gas comprises hydrogenradicals. The hydrogen radicals can be generated by any suitable meansincluding exposure of hydrogen gas to a “hot-wire”. As used in thisspecification and the appended claims, the term “hot-wire” means anyelement that can be heated to a temperature sufficient to generateradicals in a gas flowing about the element. This is also referred to asa heating element.

The second reactive gas (e.g., hydrogen), while passing the hot wire, orheating element, becomes radicalized. For example, H₂ passing a hotruthenium wire can result in the generation of H*. These hydrogenradicals are more reactive than ground state hydrogen atoms.

Next, at 112, the process chamber may be purged using an inert gas. Theinert gas may be any inert gas, for example, such as argon, helium,neon, or the like. In some embodiments, the inert gas may be the same,or alternatively, may be different from the inert gas provided to theprocess chamber during previous process steps. In embodiments where theinert gas is the same, the purge may be performed by diverting thesecond process gas from the process chamber, allowing the inert gas toflow through the process chamber, purging the process chamber of anyexcess second process gas components or reaction byproducts. In someembodiments, the inert gas may be provided at the same flow rate used inconjunction with the second process gas, described above, or in someembodiments, the flow rate may be increased or decreased. For example,in some embodiments, the inert gas may be provided to the processchamber at a flow rate of greater than 0 to about 10,000 sccm to purgethe process chamber.

While the generic embodiment of the processing method shown in theFIGURE includes only two pulses of reactive gases, it will be understoodthat this is merely exemplary and that additional pulses of reactivegases may be used. For example, a nitride film of some embodiments canbe grown by a first pulse containing a precursor gas like metalpentachloride, a second pulse with a reducing agent followed by purgingand a third pulse for nitridation. The pulses can be repeated in theirentirety or in part. For example all three pulses could be repeated oronly two can be repeated. This can be varied for each cycle.

Next, at 114, it is determined whether the metal-containing layer hasachieved a predetermined thickness. If the predetermined thickness hasnot been achieved, the method 100 returns to 104 to continue forming themetal-containing layer until the predetermined thickness is reached.Once the predetermined thickness has been reached, the method 100 caneither end or proceed to 116 for optional further processing (e.g., bulkdeposition of an metal or other metal film). In some embodiments, thebulk deposition process may be a CVD process. Upon completion ofdeposition of the metal-containing layer to a desired thickness, themethod 100 generally ends and the substrate can proceed for any furtherprocessing. For example, in some embodiments, a CVD process may beperformed to bulk deposit the metal-containing layer to a targetthickness. For example in some embodiments, the metal-containing layermay be deposited via ALD or CVD reaction of the metal precursor andhydrogen radicals to form a total layer thickness of about 10 to about10,000 Å, or in some embodiments, about 10 to about 1000 Å, or in someembodiments, about 500 to about 5,000 Å.

Suitable co-reactants include, but are not limited to, hydrogen,ammonia, hydrazine, hydrazine derivatives, oxygen, ozone, water,peroxide, combinations and plasmas thereof. In some embodiments, theco-reactant comprises one or more of NH₃, hydrazine, hydrazinederivatives, NO₂, combinations thereof, plasmas thereof and/or nitrogenplasma to deposit a metal nitride film (e.g., M_(x)N_(y)). In someembodiments, the co-reactant comprises one or more of O₂, O₃, H₂O₂,water, plasmas thereof and/or combinations thereof to deposit a metaloxide film (e.g., M_(x)O_(y)). In some embodiments, the coreactantcomprises one or more of H₂, hydrazine, combinations thereof, plasmasthereof, argon plasma, nitrogen plasma, helium plasma, Ar/N₂ plasma,Ar/He plasma, N₂/He plasma and/or Ar/N₂/He plasma to deposit a metalfilm (e.g., M).

Some embodiments of the disclosure are directed to metal precursors andmethods of depositing metal containing films. The metal containing filmsof some embodiments comprises one or more of metal, metal silicate.metal oxide, metal nitride, metal carbide, metal boride, metaloxynitride, metal oxycarbide, metal oxyboride, metal carbonitride, metalborocarbide, metal oxycarbonitride, metal oxyboronitride and/or metaloxyborocarbonitride. Those skilled in the art will understand that thefilm deposited may have a nonstoichiometric amount of metal, oxygen,nitrogen, carbon and/or boron atoms on an atomic basis. Boron and/orcarbon atoms can be incorporated from the metal precursor or thereactant.

In some embodiments, the metal-containing film comprises greater than orequal to about 95 atomic percent metal. In one or more embodiments, thesum of C, N, O and halogen atoms is less than or equal to about 5 atomicpercent of the metal-containing film.

Although the disclosure herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent disclosure. It will be apparent to those skilled in the art thatvarious modifications and variations can be made to the method andapparatus of the present disclosure without departing from the spiritand scope of the disclosure. Thus, it is intended that the presentdisclosure include modifications and variations that are within thescope of the appended claims and their equivalents.

What is claimed is:
 1. A processing method comprising exposing asubstrate to a first reactive gas comprising a metal coordinationcomplex and a second reactive gas comprising a dienophile comprising oneor more of an alkene, an alkyne or plasma thereof to form ametal-containing film through a Diels-Alder reaction, the metalcoordination complex comprising at least one ligand according to

wherein A₁, A₂, A₃, and A₄ are atoms in a 6-membered ring and areindependently selected from C, N, O, S, and P; wherein R₁, R₂, R₃, R₄,R₅, and R₆ are independently selected from the group consisting of H,amino groups, C1-C6 alkyl groups, or C4-10 cycloalkyl groups; andfurther provided that alkyl groups may optionally contain silicon. 2.The method of claim 1, wherein the substrate is exposed to the firstreactive gas and the second reactive gas sequentially.
 3. The method ofclaim 1, wherein the substrate is exposed to the first reactive gas andthe second reactive gas simultaneously.
 4. The method of claim 1,wherein the Diels-Alder reaction produces a quinoxaline derivative. 5.The method of claim 1, wherein the metal-containing film comprisesgreater than or equal to about 95 percent metal.
 6. The method of claim1, wherein the metal is selected from the transition metals from Groups7 to 11 on the Periodic Table.